A halotolerant Alcanivorax sp. strain with potential application in saline soil remediation

Abstract

Biodegradation of petroleum compounds in saline environments seems intricate and needs more attention. In this study, tetracosane was used to enrich alkane-degrading bacteria from oil-contaminated saline soils. Among the isolates, strain Qtet3, with the highest 16s rRNA gene sequence similarity to Alcanivorax dieselolei B-5(T), was able to grow at a wide range of NaCl concentrations and was shown by GC analysis to degrade more than 90% of tetracosane in 10 days. This strain has at least two alkB genes and could grow on crude oil and diesel fuel, and utilize various pure aliphatic hydrocarbon substrates (from C(12) to C(34)). Highly hydrophobic cell surfaces and lack of significant surface tension reduction in the media suggest that the main mechanism of the cells for accessing substrate is to attach directly to hydrocarbon particles. Application of this strain for remediating crude oil-contaminated soils irrigated with defined saline water demonstrated that this halotolerant bacterium could survive and grow in saline soils irrigated with NaCl solutions up to 5% w/v, with the highest hydrocarbon degradation of 26.1% observed at 2.5% NaCl. This strain is promising for future industrial applications especially in bioremediation of saline soils and wastes.

Bacterial Community Response to Petroleum Hydrocarbon Amendments in Freshwater, Marine, and Hypersaline Water-Containing Microcosms

“…Because we believe that the prevalence of Acinetobacter, Oceanospirillales, and Marinobacter in alkane-contaminated freshwater, marine, and hypersaline ecosystems, respectively, occurred because of the salinity of each ecosystem, we focused on culture-dependent methods and tested the optimal saline concentration for the growth of these bacteria. Previous studies have shown that bacteria from these genera grow over a broad range of salinities (17,48). Although the results obtained here explained the predominance of alkane-degrading Acinetobacter in contaminated freshwater microcosms (optimal growth was observed in medium without NaCl), this predominance was not true for both Alcanivorax and Marinobacter strains, which grew over similar ranges of salinity (from 0 to 15% NaCl) (Fig.…”

“…Bacterial hydrocarbon degradation in hypersaline environments has been considered a difficult process because the solubility of hydrocarbons and oxygen is reduced when salinity increases (14). To date, members of the Oceanospirillales order and Marinobacter and Martelella genera (14)(15)(16)(17)(18) have been detected in petroleum hydrocarboncontaminated hypersaline waters. Hydrocarbon-degrading bacteria have already been identified in freshwater (19), but the precise functions of bacterial strains in this environment remain unknown.…”

A meta-analysis of the publicly available bacterial and archaeal sequence diversity in saline soils

“…Halophilic bacteria and archaea thrive in saline soils because they possess enzymes endowed with unique structural features and catalytic power, enabling them to sustain metabolic and physiological processes under high salt conditions (Munawar and Engel 2012). Specific enzymes from soil halophiles are perceived to be potentially useful for a variety of applications, including the production of important biomolecules (Liszka et al 2012) and the remediation of pollutants in saline conditions (Dastgheib et al 2011). Soil halophiles are an excellent source for exploring novel enzymes possessing the inherent ability to function in high salt conditions (Singh et al 2012).…”

OPTIMASI PERTUMBUHAN BAKTERI LAUTSalinicola peritrichatus LBF-1-0025 DALAM SENYAWA ALKANA

“…Isolat bakteri laut LBF-1-0025 diamplifikasi berdasarkan sekuen gen penyandi 16S rRNA menggunakan primer universal berupa primer 9F (5' AAGAGTTTGATCATGGCTCAG-3') dan primer 1541R (5'-AGGAGGTGATCCAACCGCA-3') (Dastgheib, Amoozegar, Khajeh, & Ventosa, 2011). Kondisi Polymerase Chain Reaction (PCR) dilakukan pada 10 siklus pertama yaitu pradenaturasi 1 siklus (95 °C selama 2 menit), denaturasi (95 °C selama 30 detik), penempelan primer (65 °C selama 1 menit), dan elongasi (72 °C selama 2 menit).…”